Qualidade microbiológica da água do Lago Igapó de Londrina - PR e caracterização genotípica de fatores de virulência associados a Escherichia coli enteropatogênica (EPEC) e E. coli produtora de toxina Shiga (STEC)

This work aimed at the detection and quantification of Total Coliforms and Escherichia coli in Igapo Lake, in order to evaluate the quality of these waters as proper or unfit for recreation, in addition to the genotypic characterization of virulence factors associated with EPEC and STEC by PCR. The study area was the Igapo Lake I, II, III and IV. Samples were collected monthly from March 2011 to February 2012. The technique used for the detection and quantification of Total Coliforms and E. coli was the Colilert chromogenic substrate. In the technique of PCR, the eae and bfp genes were tested to characterize the typical EPEC pathotype; stx1, stx2, eae and hlyA the STEC pathotype and the samples that presented only the eae gene were characterized as atypical EPEC. According to CONAMA Resolution 357/2005, it has been observed that only Igapo Lake III was rated inappropriate for primary contact recreation, while for secondary contact recreation, all lakes were considered appropriate. Moreover, a strong relationship between rainfall and E. coli indices in Igapo Lake can be observed, which in dry months the quantity drastically decreases, while in rainy months the opposite relationship was observed. Of the 97 strains of E. coli isolated, two had the eae gene (atypical EPEC). None of the isolates contained genes stx1, stx2, bfp and hlyA. Thus, we hope to educate the population and public agencies of the importance of microbiological monitoring of recreational waters to prevent outbreaks of waterborne infections.